In an existing communications system, a conventional multiple system operator (MSO) network uses a system architecture including a front end/sub-front end, an edge equipment room, a fiber node, and a user. The edge equipment room and the fiber node are connected using a point-to-point analog fiber, and the fiber node and the user are connected using a coaxial cable network in a tree topology. An access network that combines a fiber and a coaxial cable is referred to as a hybrid fiber coaxial (HFC) network. An MSO provides a video service and a broadband data service for the user using the HFC network.
A broadband access device and a video modulation device of the HFC network are installed in the edge equipment room. The broadband access device and the video modulation device modulate an Internet Protocol (IP) signal into an analog radio frequency (RF) signal and are connected to the fiber node using the analog fiber. The fiber node converts an optical signal into an RF electrical signal, and then is connected to the user using the coaxial cable. The broadband access device is a cable modem termination system (CMTS) device, and the video modulation device is an edge quadrature amplitude modulation (EQAM) device. In a conventional video service architecture that is supported by an MSO network, a digital video broadcasting service and a video on demand (VOD) service undergo frequency mixing performed by an RF combiner at an edge equipment room, are transmitted to a fiber node using an analog fiber, converted to an electrical signal at the fiber node, and then transmitted to a user using a coaxial cable.
However, such a conventional HFC network has shortcomings such as an insufficient broadband data access capability. In a distributed system architecture based on a data over cable service interface specification (DOCSIS), a physical layer and/or data link layer interface of a DOCSIS front-end module (for example, a CMTS device) is moved to a coverage area of a coaxial cable at a same location as a remote node. Likewise, in the distributed system architecture, to support deployment of a video service, some functions of the EQAM device are retained at a front-end device side, or all functions of the EQAM device are implemented by a remote fiber node. If some functions of the EQAM device are retained at the front-end device side, a new protocol needs to be specified between the front-end device side and the remote node, and there is a need to support a clock synchronization function and control and manage, at the remote node, the EQAM device. As a result, network deployment becomes quite complex.